Device for the proportionate feeding of mixing ingredients to concrete and mortar mixing machines



Sept. 15, 1931. HAHN 1,823,270

DEVICE FOR THE PROPORTIONATE FEEDING OF MIXING INGREDIENTS TO CONCRETE AND MORTAR MIXING MACHINES Filed Aug. 1. 1929 Patented Sept. 15, 1931 UNITED STATES PATENT OFFIOE ROBERT HAHN, OF NEUNKIRCHEN, GERMANY DEVICE FOR THE PROPORTIONATE FEEDING OF MIXING INGREDIENTS T0 CONCRETE AND MORTAR MIXING MACHINES Application filed August 1, 1929, Serial No. 382,795, and in Sweden August 4, 1928.

The object of my invention is to enable the mixing of. granular materials such as cement, sand, mortar, and the like, where'measured quantities of each material to be mixed with another are supplied, so that adjustment may be made to take account of different density of the materials due to different sizes of particles.

My invention consists in whatever is de- 10 scribed by or is included within the terms or scope of the appended claim.

In the drawings Fig. 1 is a side elevation of a concrete mixing machine embodying my invention;

Fig. 2 is a section on the line 22 of Fig. 1;

Fig. 3 is a detail view of another embodiment of my invention than that shown in the other figures in regard to the regulating device;

Fig. 4 is a detail view in elevation of the adjusting device shown in Figs. 1 and 2;

Fig. 5 is a detail View in end elevation with parts in dotted lines, illustrating a construction having a container for both cement and lime.

The machine has for each receptacle of material to be mixed with another, a worm conveyor that is revolved to feed out the material to mix with another and by varying the rate of revolution of the worm, the proportion of one material to the other may be changed. For rotating the worm conveyor for cement, for example, the Worm shaft has a ratchet wheel h engaged by a pawl g pivoted to one arm of a bell-crank lever c which arm is engaged and moved by an eccentric disk I) on a driven shaft a, and according to the throw of the lever by the disk the ratchet wheel is turned and the worm revolved. By adjusting the arm of lever 0 relative to the disk, the stroke of the ratchet 9 can be shortened or lengthen ed. To so adjust it the horizontal arm of the lever 0 is engaged at its end by a snail cam e, on a shaft (Z, and operatively associated with concentric scale members, a rotary scale f and a fixed scale 70, so that by rotating the scale 7, the cam e is adjusted. The readings of scale 70 are in percentages toshow the variation in feed that different densities of cement require. The

readings of scale 7 show the cement proportions regardless of density.

As shown in Fig. 5, the receptacle has a hinged wall or flap, to subdivide it into compartments of different size, one for cement and the other for lime, both being delivered to the same worm conveyor, and a scale being provided to regulate the proportions.

As shown in Fig. 3 instead of the lever 0 and the eccentric 7), the crank arrangement shown in Fig. 3 may be employed. This includes a crank Z with a radially adjustable crank pin m, that has a pointer n to cooperate with a radial scale 0 with which cooperates a second scale 79.

I claim A. device for feeding ingredients to a mixing machine comprising a receptacle, a variable speed feed worm in the receptacle, a fixed scale, a relatively rotatable scale, an eccentric operatively connected with the rotatable scale and mechanism controlled by the rotatable scale for varying the speed of rotation of the worm.

In testimony whereof I afiix my signature.

ROBERT HAHN. 

